The subject matter disclosed herein relates to turbines. More particularly, the subject matter relates to an assembly of turbine static structures.
In turbine engines, such as steam or gas turbine engines, static or non-rotating structures may have certain clearances when placed adjacent to one another. The clearances between adjacent structures allow for movement caused by temperature changes or pressure changes. For instance, in a gas turbine engine, a combustor converts chemical energy of a fuel or an air-fuel mixture into thermal energy. The thermal energy is conveyed by a fluid, often air from a compressor, to a turbine where the thermal energy is converted to mechanical energy. High combustion temperatures and/or pressures in selected locations, such as the combustor and turbine nozzle areas, may enable improved combustion efficiency and power production. In some cases, high temperatures and/or pressures in certain turbine structures may cause relative movement of adjacent structures, which can cause contact and friction that lead to stress and wear of the structures. For example, stator structures, such as rings or casing, are circumferentially joined about the turbine case and are exposed to high temperatures and pressure as the hot gas flows along the stator.
It is desirable to improve turbine performance by reducing turbine clearances. In some cases reducing clearances requires accounting for eccentricity, out of roundness and part variation.